The row has rumbled on for several weeks as to whether Hock, who left Salford in February, will be able to play against his former club.
The two clubs agreed a deal which would see the 31-year-old continue to receive part of his salary from Salford while at Leigh, as long as he did not play against the Red Devils.
But Beaumont maintains that it is not up to Salford who gets picked to play for Leigh.
“There’s been a lot of speculation over that but I decide who plays for Leigh and Salford don’t decide that,” he told Sky Sports’ ‘Boots ‘n’ All’ programme.
“There is a private agreement, a compromise agreement, between Salford and Gaz, I had no knowledge of that when I signed him. If I make an agreement with another club I’ll always honour it and stick to it but I wasn’t aware of it.
“In fact, there is a clause within it that prevents Gaz even telling anyone about it so his hands were a little bit tied.
“There is some stuff to be sorted off the field with Salford but I decide who plays for Leigh and Gaz Hock will definitely play against Salford, provided Paul (Rowley) picks him, of course.
“But he is certainly available for selection and I’d be surprised if Paul didn’t pick him.”
Salford owner Dr Marwan Koukash vehemently disagreed with that assessment of the situation, however, and implied that there could be serious financial considerations for Hock, should he play against his former club.
“Gareth Hock asked to leave the club, we agreed a compromise deal with him in which we are still paying part of his salary and in return he agreed – and it is in black and white – that he doesn’t play against us,” he said.
“Now should he choose to play, that will be his business but that will put his compromise deal in jeopardy.
“It is a legal document that he has agreed to and we kept our part of the bargain.
“It surprises me Leigh claiming that they didn’t know about the deal etcetera because Gareth’s agent made it absolutely clear to us that Leigh are aware of it.
“So to start playing silly games now prior to an important game is very, very silly.”