Eddie Jones first joined Saracens as an advisor in 2006
Saracens have announced that their director of rugby Eddie Jones has left the club with immediate effect.
Club coaching co-ordinator Richard Graham has been placed in charge of the first team for the rest of the season.
Australian Jones, who is to become general manager of Japanese club Suntory, was initially due to leave Saracens in the summer.
No reason has been given for the news but Jones was known to be unhappy with the Saracens managerial regime.
Saracens have already lined up South African Brendan Venter to replace Jones, 49, in the summer.
Venter was lined up to replace Jones on 1 July as part of a controversial major restructure being introduced by the club's South African owners, which will also see 15 of the 38 senior players leaving in the summer.
Meanwhile, players from South African provincial sides the Sharks and the Stormers, who the owners also have controlling stakes in, have been approached about replacing them.
Jones described this period as "the worst he has had in rugby".
This had been Jones' second stint with Saracens, rejoining them on a part-time basis in the summer of 2007 after an initial consultancy stint in 2006, and he had stressed his commitment to the club until the end of his contract.
"Obviously, my complete focus for the rest of the English season is with Saracens," he said.
"We have six games remaining in the Guinness Premiership and a home European quarter-final as we look to finish the season strongly."
However, he also spoke of his reasons for returning to Suntory, with whom he began his coaching career in 1996.
"It's the club I started with and I've maintained close links with them ever since," said Jones.
"I look forward to the challenge. They have aspirations on the world stage."
Brendan has an outstanding knowledge of the Premiership, following his success as coach at London Irish
Saracens chairman Nigel Wray
Jones was appointed as Australia coach in 2001, taking the Wallabies to the World Cup final in 2003, but was sacked at the end of 2005 after a run of eight defeats in nine games.
He took charge of Super 14 side Queensland Reds but resigned in May 2007 after his side finished bottom of the table.
Jones was named as technical advisor to the Springboks in August 2007 and played a key role as South Africa claimed the World Cup for a second time that October.
He then returned to Saracens as an advisor after the World Cup eventually replacing Alan Gaffney as coach at the start of the current season.
Venter, who is currently a specialist coach at Saracens, will take charge of Saracens on 1 July as part of a controversial major restructure being introduced by the club's owners, which includes the overhaul of playing staff.
"Brendan has an outstanding knowledge of the Premiership, following his success as coach at London Irish," said Saracens chairman Nigel Wray.
"He has become well known and well respected at Saracens during the course of this season, after being introduced and recommended by Eddie as a specialist coach. We warmly welcome him to the club on a full-time basis."
Venter won 17 caps for his country and, during his time as player-coach at London Irish, he helped secure the club's first major trophy, the Powergen Cup, in 2002.
He left London Irish in 2003 to return to South Africa to pursue a career in medicine.
Graham has also announced he will be departing Saracens to return to Australia at the end of the season to join the national side as skills coach.