The leader of the Interior Ministry police group that killed the Rev. Jerzy Popieluszko clashed in court today with his boss, also a defendant, calling him a cunning liar.

The outburst by former captain Grzegorz Piotrowski came at the end of three days of testimony by Col. Adam Pietruszka, who has insisted that he is innocent of aiding and abetting Piotrowski and two former police lieutenants accused of killing Popieluszko, a strong supporter of the outlawed Solidarity labor movement.

Sneering at the colonel, Piotrowski said sarcastically: "I have talked about a number of Pietruszka's positive traits, and now I would like to add another, which I would put at the top of the list. That is cunning."

He then said that "Adam Pietruszka's evidence is a lie in its fundamental points."

Piotrowski repeatedly has pointed to Pietruszka as the one who encouraged the attack on Popieluszko, then tried unsuccessfully to cover it up. The colonel has accused his subordinates of fabricating evidence and misinterpreting remarks he made to them about the need to take action against the outspoken cleric.

One of the judges hearing the case at Torun's provincial court also has voiced doubts openly about Pietruszka's truthfulness, noting numerous discrepancies between his pretrial and courtroom testimony.

Pietruszka admitted today that he had lied once during investigations into the murder, but he said this had been on the orders of his superior, Gen. Zenon Platek, director of the department responsible for monitoring church activities. Pietruszka said Platek told him to mislead investigators about the timing of his discovery that a car used in the abduction belonged to his men.

This was the second time Pietruszka raised questions about Platek's possible involvement in a cover-up. He testified last week that Platek told him to do something about the car when the general spotted it in the ministry's parking lot two days after Popieluszko's disappearance.

Pietruszka said the general was not trying to obstruct the search but was merely delaying discovery of the car in case its presence at the ministry proved a provocation of some sort.

Piotrowski, who had heard Pietruszka last week disclaiming any responsibility for the crime, sat smirking today as judges and prosecutors picked apart Pietruszka's testimony.

Piotrowski cited as one lie Pietruszka's claim about a diary note dated Oct. 15 referring to leave for the accused lieutenants, Waldemar Chmielewski and Leszek Pekala. Piotrowski said he had told his boss to make it in order to cover the whereabouts of the two as they prepared to abduct Popieluszko.

Pietruszka has insisted that he knew nothing about the kidnap mission beforehand. He told the court the diary entry was made after the arrest of Piotrowski, Chmielewski and Pekala on Oct. 23 but before his own arrest Nov. 2 as a note to himself.

But Piotrowski reminded the court that he had informed investigators about the diary entry, something the captain could not have known about had it been made after his detention.

Drawing a sharp distinction between himself and his boss, Piotrowski said: "I cannot look my subordinates in the eye today for one reason only -- that thanks to my naivete and lack of foresight, I have brought them to the dock. But I at least have the awareness that since the whole tragedy began I have never taken even half a step back to hide from my responsibility."

"It is not a question of masochism or being a boy scout but one of honor," the 33-year-old police agent continued. "Perhaps I am too young and inexperienced to know, like Adam Pietruszka, that in some situations the acceptance of responsibility and the concept of honor and civil courage are out of place."