A heroic man who selflessly dived into Melbourne’s Yarra River to save a drowning stranger has said he’d do it again.

Police were called to Harbour Esplanade at Docklands at 9.20pm following reports of a man in the water.

Without a thought for his own safety, Ahmed Almohaimeed jumped into the water to try and assist the man.

“I didn’t think so much about myself. I jumped over and I tried to push him up,” Mr Almohaimeed told 9NEWS today.

The Good Samaritan said he'd save the stranger again. (9NEWS)

The incident unfolded about 9pm yesterday. (9NEWS)

The man aged in his 50s remains in a critical condition. (9NEWS)

Despite his best efforts, the stranger was too heavy and emergency services pulled both men to safety.

Mr Almohaimeed was taken to the Alfred Hospital barely conscious while the other man, aged in his 50s, was rushed to the Royal Melbourne Hospital.

The older man remains in a critical condition after suffering a suspected heart attack.

The Good Samaritan has since been praised by friends, along with delegates from the Saudi Arabian embassy who paid a special visit from Canberra.

Delegates from the Saudi Arabian embassy praised the hero. (9NEWS)

Mr Almohaimeed (far right) escaped major injuries. (9NEWS)

“What he did was a great job…and we’re very proud of him,” Doctor Gus Olwan from the Royal Embassy of Saudi Arabia said.

Mr Almohaimeed’s relative added, “he saved the old man and was a superhero”.

The investigation is ongoing, with police yet to establish the exact circumstances surrounding the near-drowning.