The brother of former EastEnders actress Gemma McCluskie beat her to death after a row over an overflowing sink, a court has heard.
The 29-year-old actress thought it was the "last straw" when her brother Tony McCluskie left the taps on at the flat they shared, the Old Bailey heard.
The prosecution said she wanted her brother to move out.
Mr McCluskie, 35, of Shoreditch, east London, has pleaded guilty to manslaughter but denies murder.
Prosecutor Crispin Aylett, QC said Mr McCluskie killed his sister, cut up her body and dumped it in Regent's Canal in east London.
He then led police on a "wild goose chase" after reporting her missing in March last year, jurors heard.
Mr Aylett said there had been tension between the siblings for some time, largely as a "result of the defendant's habitual use of cannabis - and its most toxic form, skunk".
"Gemma told a friend 'He's permanently stoned. He puts a spliff in his mouth first thing in the morning and doesn't know what he's doing'," the court heard.
The prosecutor told jurors that on 1 March last year, Mr McCluskie got up, went to the bathroom and then forgot that the taps were on in the sink.
"Unsurprisingly, Miss McCluskie was exasperated by this. She had had enough.
"Later, while she was out, her friends heard her arguing on the telephone with her brother about what had happened."
Mr Aylett said the next day, Mr McCluskie sent his sister a text pretending she was still alive and ending "Love ya xx".
Her friends had grown anxious about her and had not been able to contact her, he said.
Mr McCluskie replied to a text message from one her friends: "She didn't take the car, keys are on the side in the kitchen plus we wouldn't know if she took any clothes (as) she (has) so many!"
Torso in suitcase
He then reported her missing to police who, from details given to them by Mr McCluskie, categorised her disappearance as low risk.
The defendant also told officers that a former boyfriend owed her money and police should speak to him.
Two days later, a suitcase containing her torso was discovered in the canal in Hackney.
Miss McCluskie had been identified by a small tattoo of a bow on her body.
Over the next fortnight, her arms and legs were recovered separately from the water while her head was not found until September.
The court heard a man matching Mr McCluskie's description and holding a heavy suitcase had taken a minicab to the canal the day after her disappearance.
The prosecutor said blood was found in the boot of the car and Mr McCluskie's father and brother "no doubt with heavy hearts" said they recognised him from CCTV.
The prosecution said it did not accept Mr McCluskie's defence that he did not remember killing her.
"No doubt he did it in the heat of the moment, no doubt he soon came to regret what he had done," added Mr Aylett.
"He did everything he could to put himself beyond suspicion."
Miss McCluskie played Kerry Skinner, the niece of Ethel Skinner, in the BBC soap in 2001.
The trial continues.