Blame it on Ramzan Kadyrov's well-known Instagram addiction; the strongman leader of Russia's Chechen Republic was apparently so worried when he lost his mobile phone at a wedding that police questioned more than a thousand people into the early hours of the morning in an attempt to find it.

The human rights organisation Memorial, which has documented numerous abuses in the mountainous region of Chechnya including the murder of its own activist there in 2009, said in a statement that the loss of Kadyrov's phone occurred on Saturday at the opening ceremony for the Shira-Yurt museum constructed in the form of a medieval Chechen village. According to his hugely popular Instagram account, the "grandiose holiday" attended by "thousands of residents of the republic" saw Kadyrov meet and dance with elders, size up a shotgun and a cannon and preside over a lavish feast. The event was capped off with a traditional Chechen wedding at which Memorial said Kadyrov gave the young couple 1m rubles (£17,000).

But the festive atmosphere belied a tight security regime. Guests could not park within 1km of the village and Kadyrov's guards – members of whom have previously been accused of kidnapping, extortion, assault, rape and attempted murder – searched attendees and their cars.

As the event came to a close at about 9pm, guests were informed via loudspeaker that Kadyrov had lost his phone and officials began questioning them, said Memorial, one of the oldest and most respected Russian human rights organisations. After the crowd went home, members of the presidential administration called organisers to find out the names of those who had attended, and later that night police and regional administration employees summoned more than a thousand adults and children for questioning about whether they had seen the phone or any other lost item. Most returned home in the early morning, Memorial said.

Kadyrov's press secretary Alvi Karimov denied that he had lost his phone. "This is all a lie. It's not true. Ramzan Akhmadovich [Kadyrov] has two phones, and they are both on his desk," Karimov told Interfax on Tuesday.

Kadyrov was appointed head of Chechnya by Vladimir Putin in 2007, three years after Kadyrov's father was assassinated in that position. He is a famously active Instagram user, typically posting photos several times a day accompanied by everything from religious messages to government announcements. Favourite subjects include martial arts, shooting and fishing, festive gatherings and exotic animals such as miniature ponies, ostriches and tigers. The fun-loving strongman has even played elaborate hoaxes with his account, once posting a series of Photoshopped images to claim he had a body double who stands in for him at events.

Kadyrov has been seen in photos to have an iPhone and another gold-coloured phone of unknown make. Although the results of the reported search were unknown, Kadyrov continued posting to Instagram on Sunday.