Coloccini says he is desperate to move to St James' Park from the Riazor Stadium but his club continues to up the price.
Reports suggest that Coloccini has already agreed personal terms with the Magpies after Mike Ashley met the Spanish club's original asking price of 12m.
But Depor have now said they want 14m for the Argentina international.
Coloccini's agent: "(Club president Augusto) Lendoiro has to face up to the music and it is not right that he should not have asked for two million more.
"One day he tells me a million will be enough, but he won't accept that, because he thinks there is a million and a half.
"For Coloccini it is a shame he may miss out on the contract of his life.
"We don't want to, but if they are pushing us closer to the edge, he could walk out."
Depor coach Miguel Angel Lotina: "If he goes it will be the great disappointment of the summer.
"The team that takes Coloccini will be getting a quality footballer, and they will be playing a dirty trick on me.
"He is a tremendous footballer for what he gives on the pitch and in the dressing room." However, Lotina has has already started looking for a replacement.
"There are several players who are to our liking, but those that we like the most aren't in the Spanish league.
"We have a good idea, but we will wait to see what happens for definite with Coloccini."