A man has hired a skywriting plane to say "sorry" to a loved one in massive letters in the skies over a city.

The mystery man behind the stunt coughed up 2,000 pounds for the stunt, which was seen by thousands.

People on the streets of Brisbane in Queensland Australia were bemused to see the apology go up above the city, saying: "I'm sorry" and "♥ u xx" to a mystery person.

The pilot who flew the mission, Rob Vance of Skywriting Services Australia, told the Brisbane Times the mystery man who hired him "was calm, cool and collected."

Vance said he had flown other similar missions for apologetic clients.

He said: "It's usually along the same lines - someone saying sorry and that's basically it," he said.

"'I'm sorry Barbara' or something like that."

It is, as yet, unclear whether this latest stunt has had the desired effect - but the gesture has caused a Twitter storm of speculation over who it was meant for.