Real Madrid president Florentino Perez has hit back at Manchester United officials, blaming their lack of experience as the main reason behind the collapse of the transfers of goalkeepers David De Gea and Keylor Navas on the Spanish deadline day on 31 August after the paperwork did not arrive at La Liga headquarters on time.

The club president suggested that the Premier League giants had in recent seasons failed to secure the services of other stars like Fabio Coentrao due to the same reason.

The Spanish giants had already made an official statement on Tuesday (1 September) blaming United for the fiasco. Madrid accused United of sending incomplete data to Fifa's Transfer Matching System and taking eight hours to make minor changes to Navas' contract – leaving Real without any time to process the deal.

The Red Devils responded later with a statement of their own, denying Real's accusation and claiming Rafa Benitez's side were culpable for the transfers' breakdown.

Reiterating Real Madrid's version of events over the failed transfers in an interview with Cadena Ser, he blamed United for the time they took to return the contract and their refusal to open negotiations for De Gea earlier in the transfer window. "On deadline day we could have said that we were no longer interested in the deal because time was short to do it but we had an obligation (with De Gea) to try it – although we knew it was very difficult."

"I think they didn't have bad intentions. I think they just lacked experience. It already happened to us (two seasons ago) with Fabio Coentrao and also happened to Athletic Bilbao with Ander Herrera (the summer before the Spanish midfielder make the move when David Moyes was in charge). When this happens more than once and you see that all the operations that, according to the media, they have tried to do during the summer (which didn't go through) one believes that this happened because it is a new team with no experience."

Perez also insisted that United sent the paperwork two minutes after the end of the transfer window. "We have already explained what happened in our statement. The last day, just 12 hours before the end of the transfer window, United told us through Jorge Mendes that they would be open to negotiate. We called them (and) within half an hour the contracts were agreed."

"United didn't asked anything during the summer because we didn't even negotiate with them. United knew that we wanted him because he did not want to renew with them. His agent explained to them it was not a sports issue but he wanted to return to Spain because of family ... We didn't speak because United constantly said that De Gea was not for sale," he explained. "We are very respectful with all the clubs so when (the last day) we got the chance we tried it. We did it for many reasons but specially because the player had made a big effort (to join Real Madrid)."

"In half an hour we agreed everything. We sent them the paperwork at 1:30 and it took eight hours for them to return it. I do not think they did it with malice. They probably would be very busy but one thing that you can do in an hour takes eight (hours) for them. We received the contracts from them at 00.02 and they had sent it at 00.00. That is out of time. We, Real Madrid and Fifa have proof but we do not want to make it public," he said. "It was a disgrace. I do not want to blame anyone but we do not understand why they took eight hours to check the contracts or that they didn´t opened negations until 12 hours before the deadline."

United claimed through an official statement that they offered Real Madrid the chance to make an appeal but this was rejected. Perez said: "They said that just to get in good (with the supporters). It is just to say we offered them that but Real Madrid rejected it. But the paperwork arrived later. It was out of time. We sent to La Liga anyway, we spoke with the President and with a chief from Uefa but we saw it was impossible. Their offer (to try to help us to get the deal done) was from someone without experience.

"In the afternoon I already had the feeling that the deal was not going to happen because I knew about the lack of experience of United official in these matters," he said. "The relationship between the clubs is good but I have just to say what happened. "