D.C. Public Works Director John Touchstone, who disclosed in January that he and an aide accepted free travel and hotel accommodations for two nights in New York from a D.C. government contractor in 1984, said yesterday that he and the aide took a second trip, to Philadelphia in 1985, partly at the contractor's expense.

The contractor, Datacom Systems Corp., which receives an estimated $4 million a year from two District public works contracts, paid a total of $1,720 in hotel and other expenses incurred by Touchstone and his executive assistant, Marie Timm, for the two trips, according to department spokeswoman Tara Hamilton.

On Wednesday, Datacom was implicated in a widening scandal involving the New York City Parking Violation Bureau when a former consultant to Datacom was charged with making $20,000 in payoffs to a former New York City parking official on behalf of the firm and a Datacom vice president was charged with extorting $150,000 from a subcontractor.

A Datacom spokesman strongly denied yesterday that the firm participated in any wrongdoing and said the company is confident the vice president will be found innocent. The Datacom official said the company is cooperating with federal authorities in New York and Chicago, where a related investigation into Chicago's parking contracts is under way.

There is no indication that federal authorities are investigating Datacom's Washington contracts.

"I haven't tried to hide anything," Touchstone said in a telephone interview yesterday. "My view is that they were strictly business trips . . . . I didn't receive any benefit. It's just that [Datacom] paid instead of the [D.C.] government."

Hamilton said that Touchstone, in order to avoid the appearance of impropriety, recently reimbursed Datacom for his and Timm's expenses. Hamilton said that Touchstone has now asked the District government to reimburse him for the trips because he and Timm were on official D.C. government business on both occasions.

The District's conflict-of-interest law prohibits a city official from soliciting or accepting a gift, favor or hospitality "when it could be reasonably inferred" that the gratuity would influence the official's decision.

Touchstone said that payment of the expenses in no way affected any of his official decisions, and Datacom's spokesman said the trips were not intended to curry influence with Touchstone.

At the time of the first trip, which was a two-day visit to Datacom facilities in the New York area in March 1984, Datacom had a $300,000- to $400,000-a-year contract with the D.C. Public Works Department to collect overdue parking tickets.

Datacom paid a total of $1,000 in travel, hotel and other related expenses for Touchstone and his aide, according to Hamilton.

In July 1984, the Public Works Department agreed to award a larger, multimillion-dollar parking management contract that ultimately went to Datacom. Frederic Caponiti, a top D.C. public works parking official, has said the idea for the parking management contract intially came from Datacom when it submitted an unsolicited proposal to the city in early 1984. Caponiti said Datacom was the only firm to bid on the management contract, which is estimated to be worth $3.2 million a year.

Touchstone, as public works director, signed the parking management contract with Datacom on March 25, 1985.

The second trip involved hotel and other expenses for Touchstone and Timm for part of a trip they took to Philadelphia in July 1985, according to city officials. Touchstone and Timm went to Philadephia to meet with federal officials on an unrelated matter and decided to stay over because Datacom officials asked them to inspect the firm's parking enforcement program with the city of Philadelphia, Hamilton said.

Hamilton said Timm returned to Washington after the second day as planned, but Touchstone became sick and was forced to stay over an extra day. Hamilton said the city paid for their travel and first-day expenses and Datacom picked up $720 for their remaining hotel and other related expenses.

Touchstone did not report either the 1984 trip or the 1985 trip on financial disclosure forms for both years that he filed with the D.C. Office of Campaign Finance, according to Director Keith Vance.

Vance said he considers Touchstone's failure to report the trips "a technical violation" of the city's law on financial disclosure. He said Touchstone, who recently reported the trips, is now in compliance with the law.

Touchstone disclosed the 1984 trip publicly after a reporter asked him about it on Jan. 17.

On Jan. 21, Touchstone notified Vance about the New York trip and told Vance he had asked Datacom to inform him of any other of his expenses that the firm might have paid for, according to Vance. This led to the disclosure of the payments for the Philadelphia trip, according to Vance.

Touchstone then reported the 1985 Philadelphia trip to Vance in a letter dated Feb. 26, Vance said.

Touchstone is the second top D.C. official to recently acknowledge having travel-related expenses paid by firms doing business with the city.

Alphonse G. Hill, deputy mayor for finance, acknowledged earlier this month accepting free lodging from a city contractor and a local bankers' lobbying group in 1985. Hill has resigned from his post.

In January, federal prosecutors disclosed that Datacom had paid more than $70,000 in consulting fees to former D.C. deputy mayor Ivanhoe Donaldson, who had worked as a part-time consultant for the firm after he left the D.C. government in late 1983.

Donaldson, who is serving a seven-year prison sentence following his conviction on corruption charges, was recruited by John Brophy, a top Datacom official who is a former D.C. parking official and supporter of Mayor Marion Barry.