A husband has been brutally hacked to death with a machete in front of his pregnant wife in a suspected honour killing in India.

Pranay Kumar, 24, was leaving a hospital with 23-year-old wife Amrutha Varshini in a village near the city of Hyderabad when he was attacked on September 14.

An unidentified man was filmed on CCTV walking up behind Pranay with a machete before hacking him across the back of the neck as Amrutha watches on.

The desperate wife could be seen trying to stop the assault as Pranay slumps to the floor, but the man delivers another crushing blow to his head.

The attacker then throws away his machete and walks off as Amrutha runs inside the hospital to summon help for her stricken husband.

Despite medics efforts he succumbed to his injuries a short time afterward.

Police are investigating the attack as an honour killing which they believe was carried out because the pair were from different castes.

Amrutha was from the vaishya caste comprised of farmers and traders while Pranay was a Dalit Christian, also known as an ‘untouchable’.

The pair originally married in January, against the wishes of both of their families.

However, Pranay’s family had since accepted the union and decided to hold a reception for the two in August.

Police were alerted to the marriage after the couple invited several officers to the reception and gave the couple a warning.

Nalgonda Srinivas, deputy superintendent of police, said: ‘I had my suspicions about [Amrutha’s] father and had warned the couple.

‘When they held the reception in August, we gave out notices and had deployed a few police officers at the venue so that nothing bad happened.’

It is thought the killing could have been prompted by Amrutha posting a wedding video of the pair on Facebook.

Amrutha has told local media that she believes her husband and uncle were behind the attack. Officers are investigating but have yet to make any arrests.

Police  say Amrutha’s father was questioned in March over the possibility he would use violence to break up the marriage, but insisted he had no plans to do so.