A MAN has described how he was threatened with a gun, discovered a body and was forced to sign a forged document in one of Huntingdonshire's most sensational ever court cases. Steven Austin was giving evidence in Peterborough Crown Court against his former business partner Marcus Alder. Alder, 48, of Apple Close, Offord D'Arcy, is charged with 14 offences, including perjury, blackmail and fraud. Alder, who served for a brief period as a police office, was "obsessed with weapons" and claimed to have links to MI5. Mr Austin, of Hemingford Grey, described Alder as an intimidating man who could be verbally aggressive. Prosecutor Timothy Spencer QC alleged that Alder had tried a number of ways to get his hands on the valuable estate of Phillip Tyssen-Gee, who killed himself at his Somersham home in November 2006. His body was discovered when Alder and Mr Austin went to visit him. Alder later forged a suicide note and forced Mr Austin into signing a letter to Richard Wood, the executor of Mr Tyssen-Gee's estate. The letter wrongly claimed that Alder had been in a "loving relationship" with Mr Tyssen-Gee and that they were in a civil partnership. Mr Woods, giving evidence in court, said more than \u00A3160,000 of Mr Tyssen-Gee's money was missing at the time of his death and he was heading for "financial destitution", despite inheriting half a million pounds from his mother. A week after Mr Austin was forced to sign the letter, Alder threatened him with a gun. Mr Austin told the court: "We were driving from Ramsey to our business premises in Wyton. I remember Marcus asking me if I knew about a particular type of bullet used by the police. He didn't say a lot and I thought to myself 'Where is he taking this?' "We were on the road from Warboys and there was a turn on the left for Somersham. I didn't think we'd take it because of the speed we were going." However, he said that Alder swung the car into the turn and parked on a hard standing nearby. Mr Austin continued: "He reached behind my seat and had a hand gun in his right hand. "He said 'This is to remind you that you say nothing and do nothing'. He put the gun out the driver's side window and pulled the trigger." Mr Spencer asked: "How do you know he pulled the trigger?" Mr Austin replied: "There was an extremely loud explosion. "I just froze. I had many thoughts going through my head. I asked myself 'Is this it?' I wasn't sure how it was going to end." However, Mr Austin said that Alder acted as if what had happened was "an every day occurrence", reversed the car and continued the journey to Wyton. When they arrived back at the Uplands Industrial Estate, where they ran a used-car business, Mr Austin went straight to the toilet block. Mr Spencer asked: "Why did you do that?" Mr Austin replied: "I felt sick. I vomited. I don't know what you would do if you saw a gun, but it made me do that." The court had earlier heard how Alder had obtained finance for a number of cars in the names of women he met on internet dating sites and convinced one woman to marry him. The court heard that he told Angela Grieg on their wedding night: "I can stop pretending now - I've got you", which the prosecution said was a reference to getting access to her money. Alder later held a samurai sword to Angela's throat as she arranged a mortgage over the telephone and threatened her with a gun. After his arrest in September 2007, police found a note on a computer at Alder's address admitting his claim to Mr Tyssen-Gee's money was false. It read: "I may be a bit odd, I may be money motivated, but for the record I am not gay or bisexual... I was just after money. It is true, I am a greedy git." Following his arrest Alder applied for a credit card in the name of the deceased Mr Tyssen-Gee. A fraud analyst for MBNA told the court that the application was refused. Alder is charged with perverting the course of justice, perjury, theft, possession of an illegal weapon, two counts of fraud, two counts of intimidation, three counts of deception and three counts of blackmail. The case continues.