An EgyptAir mechanic had planted a bomb on the Russian passenger plane that crashed over Sinai Peninsula in October, Reuters has reported citing Egyptian security sources.
The exclusive report states that the detained mechanic's brother had joined the Islamic State in Syria a year ago.
Isis had claimed the taking down of the Russian chartered passenger plane Metrojet Flight 9268, saying it was an act of retribution against the Russian bombing of the outfit's strongholds in Syria.
The plane was flying from the popular resort city of Sharm el-Sheikh in Sinai to Saint Petersburg in Russia. It disintegrated mid-air shortly after take-off, killing all 224 people on board.
Egypt has so far said that it has got no evidence to confirm that the plane as brought down by an act of terrorism. But Russian authorities believed the plane was brought down by terrorists who planted a bomb in the baggage hold.
The agency added that senior security officials at the airline as well as an interior ministry official have denied any arrest has been made.
Russia's RIA Novosti also reported that sources in Egypt's Civil Aviation Ministry dismissed reports of EgyptAir employee's arrest in connection with the Metrojet crash.
"No one from EgyptAir has been arrested over this case, we have not heard of any suspects either," Sputnik News reported.
Bomb in juice can
However, Reuters said its sources confirmed the detention of the employee and two other airport policemen.
"After learning that one of its members had a relative that worked at the airport, Islamic State delivered a bomb in a handbag to that person," one of the sources said.
"According to our experts, a homemade explosive device equivalent to 1kg of TNT went off onboard, which caused the plane to break up in the air, which explains why the fuselage was scattered over such a large territory" Alexander Bortnikov, the head of Russia's FSB security service had said in November.
Weeks after the crash, Isis' propaganda magazine Dabiq claimed the plane was taken down by an improvised explosive device stashed inside a can of pineapple juice.