Relatives of the October 2015 Russian plane crash victims will sue the company from which Metrojet airline rented the fateful A321 Airbus, Russian newspaper Izvestia reported Monday. The plane operated by Metrojet (also known as Kogalymavia) crashed over Egypt’s Sinai Peninsula region, killing all 224 people aboard.

About 100 relatives of the plane crash victims are preparing to file a lawsuit against an American leasing company, International Lease Finance Corporation (ILFC). They will be claiming damages between $300,000 and $1.5 million, Igor Trunov, a lawyer representing the relatives told the newspaper, according to Sputnik News.

"We have prepared the materials to claim compensation for the victims' families from the owner of the aircraft — an American company ILFC," Trunov reportedly told Izvestia.

Although an investigation to establish the cause of the crash is ongoing, Russian and Western governments have maintained that the plane was brought down by a bomb — a theory repeatedly denied by Egypt. In December, Egypt released a preliminary report saying its investigation committee did not "receive any evidence" that showed foul play at work in the Metrojet crash.

In November, Britain said it had information that showed the plane was brought down by an “explosive device.”  A U.S. official had also said in November that the U.S. intelligence indicated the crash was most likely caused a bomb planted by the Islamic State group or an affiliate of the militant group. The same month, Russian newspaper Kommersant, citing an unnamed source, reported a bomb was placed in the aircraft’s main cabin.

"According to a preliminary version, the bomb could have been laid under the passenger seat by the window. Its operation has led to the destruction of the frame and depressurization of the cabin, which had an explosive character," the newspaper said. Following the crash, an audio message posted on social media, believed to be from Wilayat Sinai, an Islamic State group affiliate, confirmed ISIS' claim of downing the jet.

Britain and Ireland suspended all flights to Egypt’s Red Sea resort of Sharm el-Sheikh, from where the flight 9268 took off for Russia's St. Petersburg.