Two British Airways (BA) ground staff were arrested after an aeroplane was damaged at Heathrow Airport in west London, police have said.
The pair, 54 and 49, were questioned over an allegation that a baggage truck was driven into a BA jet on 9 January, BBC crime correspondent Ben Ando said.
He said police did not believe the incident was terrorism-related.
The pair have been released on bail. A BA spokeswoman said they had been suspended while the inquiry continues.
The Airbus A321 jet is currently being examined by BA engineers.
The 80 passengers due to fly on the plane had to be put on another flight.
Mr Ando said a police source had described the damage as a gash to the fuselage.
"The damage was spotted by other members of ground crew before the plane took off," he said.
"Had it got into the air with this damage it is difficult to know what could have happened - the worst case could have been a catastrophic decompression of the plane causing it to crash.
"On the other hand something more controlled could have taken place - perhaps there was no real damage at all.
"Until the engineers complete their checks it is difficult to know what could have happened."
The BA spokeswoman said: "Two members of our ground staff based at Heathrow were arrested following an incident where one of our aircraft was damaged.
"They were both questioned by the police and released on bail pending further inquiries.
"It would therefore be inappropriate to give further details.
"The two staff members have been given a precautionary suspension, without prejudice, while the police carry out their investigation."