Very hard Chess Puzzle to Solve

This is a chess puzzle that I have been trying to solve. It is white to play and mate in 4 (there are solutions that are longer and shorter, but I haven't found the one for 4 yet). I have considered moves like: be6, Qg4, and Qh3 as first moves, but I don't know where I have gone wrong.

I know that the engine says that be6 is the best move, but I have been told that there is definitely a mate in 4. (be6 is not necessarily the correct first move) 

Any help would be greatly appreciated.

I believe that there is a mate with 1.Be6+ but after Kc6 I think that you can get it down to a mate in 5 This is very hard.

Thank you for your response. I agree with that move, but I have been told that be6 is actually not the first move... Perhaps it has something to do with the queen?

There is no forced mate in 4. Only mate in 5.

There are 3 different ways I found checkmate in 5

1. Be6+  Kc6

2. a4+  Kc4 / Ka6    if Ka6 then there is Qe2 Ka7 and then b4 checkmate in 5 moves

                               if Kc4 then there is Qe2 Kc5 and then Be3 checkmate in 5 moves

                                                                      or Kb3 and then and then Nd2 checkmate in 5 moves

I don't believe that there is one in 4 moves...

It is interesting that some people believe what they are told and by that reject the engine variations. As if we are still living in the 20th century where it was OK to treat engine analysis with a healthy degree of disrepect. But now you need some truly awkward stuff to outwit the beast and a simple game mate in 4 or 5 won't do the trick!

The reason why Be6+ is a good move is because if black takes (Which is a blunder) then white will play Qe8#

i dont think there is one in 4 moves

i edited this because of typo

Guys It is DxE5

Thanks for this puzzle!

Its very challenging!

But ~ fun at the same time!