The parents of a missing businesswoman claim they did not go to the police when she disappeared because they were threatened by one of the men accused of murdering her, a court has heard.

Lynda Spence, 27, has not been seen since April 2011, but she was not reported missing until the following month.

Prosecutors allege that Colin Coats, 42, David Parker, 38, Philip Wade, 42, and Paul Smith, 47, abducted, tortured and murdered her, which the four men deny.

Ms Spence's parents, Patricia and James Spence, told the High Court in Glasgow that Coats came to their home and told them their daughter owed him £10,000 in the days after she disappeared.

Coats was "like a mad man", "banging his hands on the couch" when she got upset and mentioned getting the police involved, Mrs Spence, 56, said.

He apparently told them "I'll get years" if detectives looked into emails and files on his computer, the court heard.

Mr Spence, 68, said: "We discussed the situation about the money. My wife asked if (Coats) knew where Lynda was and he said he didn't.

"My wife got all upset and then he started losing the rag. She was saying that if Lynda owed him money then she was going to the police.

"Coats's reaction was to start banging the couch and saying 'You will not be getting any police. If the police get involved I'll get years'.

"He said 'Don't forget, I've got UDA people and London people'. It was a threat."

During her evidence, Mrs Spence said: "(Coats) started getting like a mad man, banging his hand off my couch saying 'you're not going to the police'. He said to Jim 'tell her she's going to no police'.

"He said something about if the police get into his emails he would be in trouble.

"I was just hysterical, screaming and that. That was just making him worse."

Mr Spence said he met with Coats and another man, Tony Kelly, at Rio Cafe in Partick, Glasgow, after his wife received a text apparently from Ms Spence, claiming to be in London, which said she spent Coats's money and that someone else called John Glen took £200,000 from her.

"I explained to Coats what had happened and he went pure white," he said.

"He sat there and the blood ran from him.

"I told him the wean (Ms Spence) had spent his money, had spent £10,000, that John Glen had taken £200,000 from her and she had pawned two of his watches.

"He was sitting down and got up for a minute. He said 'I've got to go outside and calm down'."

Mrs Spence also told jurors that Coats made her and her husband hand over their caravan in Burntisland, Fife because he believed he could sell it for the £10,000 Ms Spence allegedly owed him.

"When we were driving there I got upset just thinking about the memories we had there with the wean.

"(Coats) got out the car because his temper was up. He called her a scumbag and I was ready to answer back but his girlfriend squeezed my hand like 'don't'."

They were later given back the keys to the caravan because of unpaid fees associated with it, the jury heard.

Mr and Mrs Spence said they reported their daughter missing on May 13 2011 after a detective visited their home and told them he was looking for Ms Spence in connection with fraud inquiries.

They admitted to the court that they did not tell police everything they knew initially but gave another statement on June 2 2011 when Ms Spence's phone was found in a bin in Kilbirnie, Ayrshire.

"I knew when her phone was found in that bin that there was something no right," Mr Spence said.

Solicitor general Lesley Thomson asked him: "So you gave another, lengthy statement at Partick police station and this time you told the truth?"

He replied: "Yes."

Mr and Mrs Spence told Ms Thomson that "the wean" refers to their daughter.

Coats, Parker, Wade and Smith are accused of taking Ms Spence from a street in Glasgow on April 14 2011. They are said to have held her hostage at a flat in West Kilbride, Ayrshire where they allegedly bound, gagged and assaulted her in an apparent attempt to extract financial information from her.

The trial before Lord Pentland continues.