Former Richmond AFL player Jake King has been charged with making threats to kill, while Hawthorn player Tyrone Vickery is being investigated over extortion claims.
King and his former Richmond teammate Vickery were arrested on Wednesday afternoon.
King, 33, was charged with threats to kill, making threats to kill, two counts of threats to inflict serious injury and two counts of using a carriage service to harass.
He was bailed and will appear at the Melbourne Magistrates Court on November 15.
Vickery, 27, was released pending further investigations.
Fairfax Media reports Vickery had enlisted King to help him recover $100,000 he believes had been stolen from his Hawthorn restaurant business.
King was arrested at City of Ink, the tattoo parlour he co-owned with former bikie and underworld figure Toby Mitchell in South Melbourne.
Police also raided properties in Wheelers Hill and Thornbury.
Victoria Police said detectives arrested a 33-year old man from Thornbury and a 27-year-old from Wheelers Hill on Wednesday.
"Hawthorn Football Club is aware that Ty Vickery is assisting police in an investigation. As the matter is under investigation the club will not be making further comment at this time," Hawthorn said in a statement.
Ruck-forward Vickery played with King at Richmond after being drafted by the Tigers in 2008 but was traded to Hawthorn for this season.
Vickery has struggled in his first season with the Hawks, booting just two goals in six matches and twice being dropped to the VFL.
His Russian-born wife Arina Rodionova was the only Australian to win her first-round match at Wimbledon, beating Russian No.16 seed Anastasia Pavlyuchenkova on Tuesday.
King was forced to retire midway through the 2014 season with a serious toe injury.
After making his AFL debut in 2007 at the age of 23, King went on to play 107 matches for the Tigers as a tough-tackling small forward.