Tehran, Jan 14 (IANS): An Iranian judiciary spokesman said here on Tuesday that the Islamic Republic has arrested some people related to the January 8 "unintentional" downing of a Ukrainian airliner that killed all the 176 people on board.

"So far, comprehensive investigations have been carried out from the relevant people, and every day until late night, the expert teams of the Judiciary are busy interrogating, investigating and collecting documents," Xinhua news agency reported citing Gholamhossein Esmailias saying the the media.

He said that the black box of the plane has been sent to France to be decoded.

In reading the data on the black box, Iranian and Ukrainian experts will be participated.

The data to be extracted from the black box will help "significantly" to the investigation process, he said.

He noted that "the Judiciary is after unearthing the fact and practicing justice".

The Ukraine International Airlines (UIA) flight PS75 crashed shortly after taking off from Tehran, killing all the 176 people on board.

Three days later, Iran's Islamic Revolutionary Guard Corps admitted that one of its missiles had downed the Kiev-bound plane due to "human error" and mistaking it for a US cruise missile.