Last week, eight division world champion Manny Pacquiao announced that he was fighting Lucas Matthysse for the WBA 'regular' welterweight title on June 24 in Malaysia - but doubts quickly emerged over the self-promoted bout.

Pacquiao, 39, said that he will be co-promoting the fight along with Golden Boy Promotions, which represents the 35-year-old Matthysse.

The boxer's long-time promoter, Bob Arum of Top Rank, says Pacquiao is still under contract with his company and warned that the Kuala Lumpur card was not a done deal.

According to Arum, the investors for the event have yet to come up with the money - and also assured that Top Rank would be involved.

“Matthysse is one of the guys that Manny is thinking about fighting. There are others,” Arum told BoxingScene.com.

“The Malaysia part is up in the air. I don’t know these Malaysian people. If they put up the money, it’ll happen, happily. But do I know whether the money will be put up? No, I don’t,” Arum added.

Pacquiao's representatives have yet to respond to Arum’s comments, but they've made claims in recent interviews that his contract with Top Rank is now expired.

On Monday, Pacquiao stated to reporters that his contest with Matthysse was "99%" done and he expects to hold a press conference in Manila in early April, and says Matthysse and Golden Boy CEO Oscar De La Hoya will both be present at the presser.

Pacquiao has been out of the ring since last July, when he lost an upset twelve round unanimous decision to Jeff Horn in Brisbane.

The Filipino superstar is so confident the Matthysse fight will push through, that he actually began training for the bout.

“I started early because my last fight was in July last year. My opponent is a reigning WBA champion so I must be in tip-top shape when I climb up the ring,” Pacquiao said to GMA News.

“I started doing just a light workout to boost my stamina, speed and power. Training at the boxing gym will begin in the middle of April.”