The man arrested over the suspicious disappearance of elderly campers who were having a secret affair may have sold his trailer, with police urging the new owner to come forward. Jetstar pilot Gregory Lynn, 55, has been held in custody since Monday and is being questioned about the campers, who vanished 20 months ago in Victoria's high country. Flynn was arrested on Monday night by specialist police at a remote campsite in Arbuckle Junction, 280km northeast of Melbourne. His Nissan Patrol four-wheel-drive has been seized but police are yet to track down the man's trailer. Detectives believe the silver-coloured trailer was sold last year between March and July and have issued an appeal to anyone who bought one at that time matching the description to come forward, Chief Commissioner Shane Patton said. 'If they've received one or purchased one and ... they don't absolutely know who they purchased it from or how they came into possession of it - there might be something suss about it - if they could contact Crime Stoppers that would be fantastic,' he told Melbourne radio 3AW on Thursday. A mid-1990s model Nissan Patrol (pictured) is central to the investigation after being captured on CCTV near where the couple went missing. Police are also trying to locate the silver trailer which they said was sold between March and July 2020 The 4WD (pictured in a police sketch) has roof racks, side steps, off-road tyres and a bulbar. The box trailer is 'fairly standard' but has been fitted with 'off-road wheels', police said Mr Patton confirmed the man, a stood-down check captain with budget airline Jetstar, was spoken to by police previously before his dramatic arrest. The Victoria Police boss stressed there was 'no urgency' to lay charges against him, noting a person can be held in custody for 'a reasonable time' with no set limit under the Crimes Act. Jetstar pilot Gregory Lynn, 55 (pictured with wife Melanie), was arrested by heavily armed police in a dramatic operation on Monday over the disappearance of Russell Hill, 74, and Carol Clay, 73 'We're not rushing into anything here,' he said. 'This is the most complex investigation I've ever been briefed on.' Despite the arrest, Commissioner Patton said the investigation was 'still reliant' on members of the public to provide information. Though he added he was confident the mystery over what happened to the campers would be solved. Lynn has been stood down from his job with the airline saying it will assist investigators if needed. Investigators seized his 4WD following a public appeal for a blue late 90s Nissan Patrol, which was captured on CCTV in the area the night Mr Hill and Ms Clay vanished. Although the pilot's Nissan Patrol is the same make and model as the one police were looking for and has the same roof rack - it is beige, not blue. Police are investigating whether he repainted the car. Google Maps images show, in 2019, there was a blue Nissan Patrol parked in Mr Lynn's driveway. Another image taken this year reveals an identical 4WD but coloured beige. Witnesses reported a number of sightings of the vehicle, including near the campsite, with police yet to confirm they have tracked down the driver or excluded them as a person of interest. Russell Hill (pictured left) and Carol Clay (pictured right) went missing from a campsite in Victoria's high country in March 2020 A 55-year-old man suspected of involvement in the disappearance of the missing couple was arrested on Monday Police believe the pair may have had an altercation with another camper, possibly the driver of the blue 4WD. It was towing a trailer and was heard performing a 20- to 30-point turn on a narrow track the night the pair vanished. Mr Hill and Ms Clay were last heard from on March 20, 2020 while camping in the Victorian Alps. Mr Hill left his Drouin home on March 19 and picked up Ms Clay from her home in Pakenham in his white Toyota LandCruiser. On March 20, Mr Hill made a call via high-frequency radio saying he was at Wonnangatta Valley. During the call, the experienced outdoorsman said he was having radio transmission issues. Ms Clay, a former Victorian Country Women's Association president, told friends she was heading away and expected to return home on March 28 or 29. Investigators were told the couple were camping together at Wonnangatta River near the Wonnangatta camping ground. Campers found Mr Hill's car destroyed by fire at their campsite near Dry River Creek Track on March 21. The pair have not been seen or heard from since. The beige off-roader was taken by police on Monday at a remote campsite in East Gippsland where heavily armed officers swooped on the suspect, north of Sale All rights reserved for this news site (dailymail) and under his responsibility