Nick Gordon denies he contributed to Bobbi Kristina's death

The boyfriend of Bobbi Kristina Brown has called a lawsuit accusing him of contributing to her death "false and slanderous".

It was alleged Gordon gave the 22-year-old a "toxic cocktail" before putting her face down in a bath tub filled with water.

Bobbi Kristina, the daughter of Whitney Houston and Bobby Brown, died six months later after suffering irreversible brain damage.

Gordon's lawyers Joe Habachy and Jose Baez said the allegations are baseless and that Gordon was "heartbroken".

No charges have been brought in relation to Bobbi Kristina's death.

The Fulton County Medical Examiner's office said an initial post-mortem revealed "no significant injuries".