Armed Crime Squad detectives are today announcing a reward of up to $350,000 for information following an aggravated burglary at a Mount Dandenong hotel back in 2014.

Investigators have been told two staff members were locking up the Mount Dandenong Tourist Road hotel on Saturday 22 March when two unknown men, wearing balaclavas and gloves, pushed their way through the rear door about 2am.

The offenders began assaulting the male and female employees with an unknown weapon.

Whilst the pair was trying to get away from the offenders, the man was dragged across the floor and further assaulted.

Both offenders stole cash, a wallet and some jewellery before fleeing through the rear door.

The offenders did not exchange any words with the victims or make any demands during the attack.

The man suffered a fractured eye socket and serious lacerations to his head while the woman suffered a fractured skull and lacerations.

Both were taken to hospital for treatment.

There was no CCTV footage at the venue however the offenders are described as being solid build and were wearing dark-coloured clothing.

A reward of up to $350,000 will be paid, at the discretion of the Chief Commissioner of Police, for information leading to the apprehension and subsequent conviction of the person or persons responsible for the assault of the pair.

In appropriate cases, the DPP may consider, according to established guidelines, the granting of indemnification from prosecution to any person who provides information as to the identity of the principal offender or offenders in this matter.

Any payment of a reward will be subject to the applicant signing a deed of confidentiality prior to payment.