The Arsenal player, who cost the Gunners 15 million pounds (20 million dollars) when he arrived in London two and a half seasons ago, tweeted ‘it’s done’ as he prepared to head back to his former club amid reports Zenit had agreed to pay a fee of around 1.5 million dollars and also pay his wages.
Arsenal coach Arsene Wenger had previously insisted that the Russian would be staying in London although the 30-year-old has come in for criticism from fans for some recent below-par performances.
This season he has been a fringe player, generally appearing from the bench.
And with the Russian transfer window shutting Friday night Zenit made their move, saying in a statement on their website that “Arshavin is back!”
The club added: “FC Zenit welcomes the return of Andrey Arshavin to St Petersburg.”
Arsenal said in a statement: “Everyone at Arsenal wishes Andrey well during his spell with Zenit.”
Arshavin has scored 30 times in 133 appearances for the Gunners since joining in February 2009, including four goals in a 4-4 draw with Liverpool at Anfield in his debut season.
He also scored the winning goal against Barcelona in last year’s 2-1 Champions League victory at the Emirates Stadium.
The Russia captain returns to his home city and former club, managed by Luciano Spalletti, in order to maximise his opportunities for regular first-team football ahead of Euro 2012 in June.
Meanwhile, Blackburn Rovers defender Christopher Samba on Friday completed his move to Russian side Anzhi Makhachkala, the English Premier League club announced.
Blackburn refused to disclose the fee, but reports in England suggested the deal was worth £12 million (14.1 million euros) on a four-year deal.
The 27-year-old Congo international defender had made it his intention to leave struggling Rovers and had previously been linked with a move to Tottenham and QPR.
Samba’s move was made possible by the Russian transfer window still being open until midnight on Friday.
He will link up with Dutch coaching legend Guus Hiddink, who took charge of the ambitious Russian team last week.
“It was quite sudden and a little bit anxious. I see it as a new challenge,” Samba told Sky Sports News.
“It’s a little club who want to become a very big one in Russia. A very powerful owner wants to transform the club and bring the club to greatness.
“They have brought in Samuel Eto’o and Hiddink to transform the club.”