Russian billionaire Alisher Usmanov has upped his stake in Arsenal to become the club's second largest shareholder.
Usmanov bought an initial 14.65% holding last month
Red and White Holdings Ltd, which is co-owned by Usmanov and business partner Farhad Moshiri, now have 21%, with Danny Fizman possessing 24%.
Arsenal chairman Peter Hill-Wood has said the club's major shareholders have no intention of selling their stakes.
Usmanov first bought into Arsenal in August when he paid David Dein around £75m for his 14.65% holding.
This move is best seen as one of a series of complex chess moves in a game being played with the Arsenal board
BBC sports editor
Former vice-chairman Dein left the club in April over differences with the board over investment possibilities, with American businessman Stan Kroenke's potential involvement thought to be the main sticking point.
But Dein is now the chairman of Red and White Holdings and looks certain to remain a key figure as the saga unfolds, even though there is also still no agreement between him and the board regarding the settlement of his contract.
BBC sports editor Mihir Bose says Usmanov's move, announced to the Stock Exchange on Tuesday morning, is significant and believes he is likely to continue gradually upping his stake by buying more shares from smaller shareholders.
"This move is best seen as one of a series of complex chess moves in a game being played with the Arsenal board.
"When he entered the chess game by buying Dein's shares, he said he ruled out bidding for Arsenal for six months.
"However this self-denial had four conditions and one of them was if the board tore up that lockdown agreement.
"But for the moment there is no indication that any board member is tempted by the riches Usmanov may offer.
"Hill-Wood has said he is willing to talk to Usmanov about any proposals he may have for the club.
"Usmanov has not asked for a meeting yet but the board would like to know what his plans are."
Arsenal manager Arsene Wenger added that the latest development would have no affect on his position.
"I'm responsible for the results at the club and not for the rest," said the Frenchman.
Meanwhile, Arsenal release their financial results next Monday, with their turnover set to pass £200m.
They would be the first Premiership club to do so, and it would reflect the fact their move to the Emirates Stadium has helped them cut the financial gap to the likes of Premier League rivals Manchester United and Chelsea.