The two men being questioned over the death of an army cadet who fell to his death when his parachute was sabotaged are fellow members of his skydiving team.
Humberside police were given a 12-hour extension yesterday lunchtime to continue interviewing the two 19-year-olds, who were part of the three-man team called Black Rain and were pallbearers at Stephen Hilder's funeral.
Mr Hilder, 20, from Hereford, fell to his death after both his main parachute and the reserve were allegedly cut deliberately. Mr Hilder, a veteran of more than 200 jumps, had had been taking part in the National Championships of the British Collegiate Parachute Association.
The two men being questioned, David Mason and Adrian Blair, performed mid-air manoeuvres with Mr Hilder before peeling off to deploy their parachutes.
After jumping from the aircraft the trio completed 19 different moves in less than a minute as they hurtled downwards from 13,000ft.
"Part way through the dive we all made eye contact and it was just a feeling of 'Yes! This is amazing'," said Mr Mason said in an interview after Mr Hilder's death. "Whoever could carry this out needs to be caught and caught fast. This is the one that scares me most because you don't know if it could happen again."
The three men separated at about 4,000ft from the ground above Hibaldstow airfield in North Lincolnshire on 4 July. All three men were students at the Defence Academy, which forms part of the Royal Military College of Science at Shrivenham, near Swindon. The pair had been reportedly persuaded to take up skydiving by Mr Hilder. After the accident, Mr Blair told a website dedicated to the sport that the "person who did this should never leave the ground again". He said that it had seemed like their best ever jump. "They [the culprit] should have to spend the rest of their lives thinking about the loss to Steve's family and how they stopped a guy from fulfilling his dreams."
"I kind of knew in the back of my mind I hadn't seen Steve's purple canopy in the air," said Mr Blair. "I knew it had to be him."
Two days after Mr Hilder's death, Mr Mason and Mr Blair jumped again in honour of their friend. They both appeared on Yorkshire Television last week following a fresh appeal for information by police.
Detectives have interviewed hundreds of people since Mr Hilder's death, including family, friends, teachers and fellow students at the academy.
Police hunting his killers appealed to all members of the British skydiving community for help via a two-page letter published in the October edition of SkyDive magazine.
Video footage of Mr Hilder moments before he plunged to his death was shown on the BBC1 Crimewatch UK in July. The footage showed Mr Hilder giving a thumbs-up shortly before jumping from the plane.
Humberside police declined to confirm the identities of the men. A spokesman said the two were arrested in Scunthorpe.