The relationship between Nikki Hamblin and Chris Pilone as athlete and coach has been severed again. This time, it is expected to be for good.

Despite attempts at mediation by Sparc, Pilone has confirmed he is no longer coaching the Commonwealth Games 800m and 1500m silver medallist.

It contrasts sharply with his joy on the night in Delhi when Hamblin completed her double. Moments after she crossed the line in the 800m, Pilone jumped up and down, screaming "she was like Kiwi winning the 1983 Melbourne Cup", in reference to her come-from-behind second place down the home straight.

The result etched the 22-year-old a place among the greats of New Zealand athletics as just the second Kiwi woman - Lorraine Moller did it in Brisbane in 1982 - to win two individual medals on track at the same Games.

Pilone referred to their fractious relationship after the 1500m silver and received a furious rebuke from Hamblin. He then divulged Hamblin had spoken to him the night before the 800m.

"I'll never give any hints of what goes on between athlete and coach but I was proud of her. She got herself back mentally," he said. "She'll clonk me because I have said she is difficult to coach but it is important not to be judgmental of her."

Hamblin was in the background during that interview. She half-joked she was "just checking what he is saying".

The relationship has broken down further. Pilone would not elaborate on his initial statement that he has ceased coaching Hamblin. Hamblin did not return calls or messages. Athletics New Zealand (ANZ) high performance manager Kevin Ankrom is believed to be monitoring her programme in the interim.

Sparc high performance manager Marty Toomey says they are assessing the situation but have not intervened - other than to offer mediation.

"We were alerted last month. We're consciously working through it but otherwise it has been a case of hands off. All athlete-coach relationships face challenges at certain points. Some work through it, some don't."

ANZ is understood to be keen to retain Pilone's services as they try to generate another London Olympics contender to mix it with Valerie Adams and Nick Willis.

Sources say Hamblin may struggle without Pilone. While she succeeded in Delhi, her 2010 best times were still well behind in world terms. She was the 28th fastest individual in the 800m; in the 1500m, she was over eight seconds off the top pace.

Pilone is acknowledged as an uncompromising taskmaster but the consensus is he gets results, as Hamish Carter could attest with his Athens Olympics triathlon gold medal.

Pilone worked with Hamblin for four years but started coaching her full-time only when her previous coach Nick Nicholson died suddenly in 2009.

Hamblin was the first woman home in a mixed 3000m race on New Year's Day at Tauranga Domain.