Glasgow: The Commonwealth Games were rocked by a first doping case on Tuesday on a day when Australia stayed on course to sweep all six gold medals on offer in the relays on the final day of swimming at the Commonwealth Games.
There were gold medals early on for Canada`s Catharine Prendrel in the women`s mountain-bikes and Anton Cooper of New Zealand in the men`s equivalent.
David Chapman in the men`s 25m rapid fire pistol and Adam Vella in the trap brought two more shooting golds for Australia, while England took the men`s team gold in gymnastics.
The doping case involved Nigerian weightlifter Chika Amalaha who was provisionally suspended from the Games after testing positive in a drugs test taken after she won gold in the women`s 53kg category, the Commonwealth Games Federation announced.
The 16-year-old Amalaha provided an `A` sample on July 25 which revealed traces of diuretics and masking agents.
She will have a `B` sample tested at a laboratory in London on July 30.
In the pool, the Australians were fastest in the morning session in both the men`s and the women`s 4x100m medley relays, having previously taken gold in the men`s and women`s 4x100m and 4x200m freestyle relays.
However, South Africa were expected to challenge for top spot in the men`s event with butterfly specialist Chad Le Clos to come into the team that qualified fifth fastest.
Games table toppers Australia have already won 17 golds in the pool with the men`s and women`s 4x100m individual medleys among the final eight titles on offer.
Scotland`s 400m individual medley Commonwealth champion Dan Wallace laid down a marker in qualifying for the 200m medley final on Tuesday as favourites le Clos and Thomas Fraser-Holmes just sneaked into the final.
Wallace, who also helped Scotland to silver in the men`s 4x200m freestyle relay, was second fastest behind Australia`s Daniel Tranter.
"It was very good. I just had fun racing against Chad," said Wallace.
"I will just go in tonight, not hold back and hopefully pick up another medal."
However, Le Clos showed the first signs of his heavy programme during the week in Glasgow as he qualified down in seventh as he goes for his sixth medal and third gold of the meet.
"That was pretty hard. I was a bit tired this morning," said the South African.
Jazz Carlin of Wales also felt the effects of her surge to 800m women`s freestyle gold on Monday night as she qualified down in sixth for the 400m freestyle final.
New Zealand`s Lauren Boyle, who finished runner-up to Carlin on Monday, qualified fastest, whilst Scotland`s Hannah Miley also ensured she made another final on home soil with the fifth fastest time.
In the track and field Olympic champion David Rudisha of Kenya cruised into the semi-finals of the men`s 800m after safely negotiating his heat.
The world record holder set the fastest qualifying time of 1min 46.89sec and was left happy with his outing.
"Today was all about qualifying for the second round tomorrow," said Rudisha, whose staggering 800m run in just shy of 101 seconds was the stand-out performance on the track at the 2012 London Olympics.
Earlier on the track, the men`s 110m hurdles was blown wide open when England`s defending champion Andy Turner pulled up and Jamaica`s Olympic bronze medallist Hansle Parchment was a non-starter.
With Parchment failing to even make it to the start line, the field has now been opened up, and Jamaica`s Andrew Riley, Barbadian 2009 world champion Ryan Brathwaite and England`s William Sharman will all fancy their chances in the final at Hampden Park later Tuesday.
In the evening session the women`s 400m features a great field including defending champion Amantle Montsho of Botswana, also the 2011 world champion, and in-form Jamaican Novlene Williams-Mills, who has racked up three Diamond League wins this season.
Elsewhere, Kenya will be hoping for track golds in the 1,500m and 10,000m through Hellen Onsando Obiri and Emily Chebet respectively.
The weightlifting has medals on offer in the men`s 94kg and women`s 75kg.
The men`s competition sees local hope Peter Kirkbride attempting to win Scotland`s first lifting medal in 52 years, going one better than the silver he won in Delhi 2010.
The women`s 75kg final looks set to be a straight shoot-out between Canada`s Marie-Eve Beauchemin-Nadeau and Samoan Mary Opeloge.