Testimony from Democratic Party deputy chairman Evan S. Dobelle was on factor that led to the probe of Carter campaign manager Tim Kraft for alleged use of cocaine, an informed source confirmed yesterday.

"Evan feels strongly that there is nothing he said that warrants . . . this type of investigation," said the source, who has spoken recently with Dobelle. t". . . He thinks that to have this process be taking place from anything he said is utterly ridiculous." The appointment of a special prosecutor to investigate Kraft was required under a new post-Watergate-era law that was designed to assure that allegations of wrongdoing by public officials would not escape investigation.

Dobelle's information concerning Kraft was given to a federal grand jury under pressure from the prosecutor, the source said, in confirming a report that was first published yesterday in The New York Times. The source said, however, that it is not certain Dobelle was the only source of the information that led to the Kraft probe, adding that "it's not a direct line from th [Dobelle] testimony to the grand jury to the appointment of a special prosecutor."

The source provided no details of Dobelle's testimony, in confirming The Times account of how Dobelle had first declined to answer questions concerning Kraft before being pressured by the prosecutor to respond. Dobelle's testimony under oath came last spring during a day-long appearnace before a federal grand jury in New York that was looking into allegations that former White House chief of staff Hamilton Jordan had used cocaine on a visit to a Manhattan discotheque in 1978. A special prosecutor concluded there was insufficient evidence to indict Jordan.

Kraft, who was a senior White House aide in 1978 when the incident involving him allegedly took place, has denied categorically that he used cocaine. He took a leave of absence from his position as national campaign manager of the Carter-Mondale re-election committee. Yesterday, Carter-Mondale officials announced that Les Francis, 36, executive director of the Democratic National Committee, will assume a number of the campaign duties formerly performed by Kraft.

Dobelle, 35, had served as the first chairman of the 1980 Carter-Mondale campaign, until Jordan ordered Kraft transferred from the White House staff to the campaign staff to assume many of Dobelle's organizational duties. This touched off a rivalry between Dobelle and Kraft, and Dobelle was known to be upset at having been pushed into a lesser role at the campaign committee.

In his appearance before the grand jusy, according to the source who confirmed The Times report, Dobelle initially declined to answer when asked by a prosecutor about possible drug use by Kraft. Instead, Dobelle asked permission to consult with his attorney, who was outside the grand jury chamber.

When he returned, Dobelle read a statement declaring that since he was appearing to testify in the Jordan case, he did not consider questions about Kraft revelant.

But the prosecutor, after conferring with Dobelle's attorney, said he did consider the quesitons relevant. Dobelle was again asked about Kraft. And this time, with the grand jury foreman instructing him to respond, Dobelle answered the questions.

Justice Department officials have refused to comment on the case, but one source familiar with it said yesterday that an eyewitness account from Dobelle or someone else would be required to trigger the special prosecutor provisions of the Ethics in Government Act.

Even if the allegation is supported by eyewitness accounts, the likelihood of an indictment on the misdeanor charge is considered slim by Justice Department officials because simple possession of cocaine for personal use is rarely prosecuted in any federal district.