Two people have died after a gender reveal stunt ended in a plane crashing into the sea.

The plane was carrying a banner revealing the gender of a family's baby as they watched from a boat.

Authorities say that both the pilot and co-pilot were killed in the crash which occurred on Nichupte Lagoon off Cancun, Mexico on March 30.

In video footage of the incident, one of the guests can be heard joking in Spanish about a potential crash, saying ‘as long as it does not fall on us’.

The Federal Civil Aviation Agency has launched an investigation.