A building worker on trial accusing of murdering a grandfather with a kitchen knife told a jury he was totally innocent of the crime.

Jacek Adamczewski said he did not stab Roman Copija and did not see anyone else inflicting the fatal wound.

Adamczewski, 43, and Tina Bell, 45, both of Wetton Court, Laisterdyke, Bradford, deny murdering Mr Copija on the driveway of his home at about 10pm on July 14.

Mr Copija, 48, was certified dead at the scene after a 10cm knife was driven into his chest, a jury at Bradford Crown Court has heard.

The Crown’s case is that he was fatally stabbed in Thornbury Avenue, Bradford, by Adamczewski or Bell, who had been living together since May this year. Yesterday, Adamczewski told the jury he came to the UK from Poland in 2006 and moved to Bradford the following year.

He said he had worked with Mr Copija and did his shopping for him because his English was better.

“I like Roman. He is my very good friend,” he said.

Adamczewski said Mr Copija began calling him names after their employer gave him more responsible jobs to do.

He told the jury the older man was “an aggressive lunatic” when drunk, fighting people and attacking them.

Adamczewski, who had never before been in trouble with the police, said Mr Copija slapped him twice on his left ear after he and Bell walked to Thornbury Avenue.

He said he did nothing back. He had no weapon and he turned straight away and walked back home.

After he was charged with murder, Adamczewski told the police Bell had a kitchen knife with her that night.

He said she took it from the pocket of her trousers and playfully prodded him with it.

He tried to take it from her but failed to do so.

Adamczewski told the court he did not mention the knife at first because he was trying to protect Bell, who had told him she was expecting their baby.

Asked by Paul Greaney QC, barrister for Bell, why his DNA was on the knife handle, he said he used it to cut sandwiches.

The trial continues.