Router forensics

I am investigating a data breach in the company I work for. Seems that the intruders managed to access a server from the internal network by compromising a router witch supports PPTP vpn and using this router as a pivot to the server.

Obviously the logs of the router had been cleared.

Could I some how recover the deleted logs ?

I must mention that the router is an asus rt n53 and had a weak password.

Thanks