Encke, the winner of the Group 1 English St. Leger Stakes last September, was among seven horses formerly trained by Mahmood Al Zarooni who have been banned from racing for six months after testing positive for steroids in recent out-of-competition testing, the British Horseracing Authority announced Monday.

Military Attack, one of the stars on the Hong Kong circuit this year, extended his winning streak to four races with a convincing victory in Sunday’s $2.4 million Singapore Airlines International Cup at Kranji Racecourse in Singapore.

A 5-year-old Irish-bred gelding by Oratorio, Military Attack (2-1) won the Group 1 International Cup over about 1 1/4 miles on turf by 3 3/4 lengths over 18-1 Dan Excel, another Hong Kong-based runner. Mawingo, a 26-1 outsider who raced in Australia earlier this year, finished third in the field of 13. Pastorius, the 2-1 favorite, was 12th.

Farhh finished second in four Group 1 stakes during his 2012 campaign, but won at the highest level in his first start of 2013, scoring a sharp victory Saturday at Newbury in the Group 1 J.T. Lockinge Stakes.

Beaten Up, a Group 3 winner in England in 2011, won the richest and most prestigious race of his career in Saturday’s Group 1 Doomben Cup at Doomben Racecourse in Australia.

Ridden by Leith Innes for trainer Chris Waller, Beaten Up (8-1) finished three-quarters of a length in front of 3-1 favorite Foreteller in the field of 13. The $490,000 Doomben Cup was Beaten Up’s fourth start in Australia.

The comeback of former British champion jockey Frankie Dettori from a six-month drug suspension has been postponed from Monday until later in May after French racing officials told their counterparts in Brtain on Friday that the rider must first meet with their medical committee.

Dettori had hoped to resume rising at Leicester, England, on Monday.

In a statement, the British Horseracing Authority said that they had yet to receive clearance from French officials.

Sunday’s Group 2 Italian Derby at Capannelle Racecourse may go to top Italian trainer Stefano Botti by default. He trains five of the 12 runners in the race over 1 3/8 miles on turf.

Botti has a strong team in the Italian Derby, a race that consists largely of Italian-based horses. The race is worth $435,360 to the winner.

Botti’s team includes the stakes winners Biz the Nurse and Celticus. Celticus won the Premio Emanuele Fililberto over about 1 1/4 miles on heavy turf on April 2.

Libertarian, one of the two longest shots in the field, upset the Group 2 Dante Stakes on Thursday at York.

The Dante is considered a prep race for the Epsom Derby, but few will be rushing to back Libertarian in the big race. While Libertarian is by the same sire – New Approach – as Derby favorite Dawn Approach, Thursday’s victory was just the second of his career and first in a stakes race, where Dawn Approach is a multiple Group 1 winner, and a perfect 7 for 7.

Red Cadeaux, second to Animal Kingdom in the Dubai World Cup in March, will race in his fourth different country in as many starts in Sunday’s $2.4 million Singapore Airlines International Cup at Kranji Racecourse in Singapore.

A 7-year-old gelding based in England with trainer Ed Dunlop, Red Cadeaux was third in the Grade 1 Tenno Sho over about two miles in Japan on April 28. Last fall, he was eighth in the Melbourne Cup in Australia and eighth in the Japan Cup at Tokyo in November before winning the Hong Kong Vase in December.

Liber Nauticus will have a perfect record when she starts in the English Oaks at Epsom Downs on May 31.

On Wednesday, Liber Nauticus made her first start of 2013 and her stakes debut in the $112,870 Musidora Stakes for 3-year-old fillies at York Racecourse, winning by 1 1/2 lengths in the Group 3 race over about 1 5/16 miles.

Ridden by Ryan Moore, Liber Nauticus (4-6) stalked the pace for the first mile, took the lead with a quarter-mile remaining, and held off 11-1 Romantic Settings, who finished second. Woodland Aria was third in the field of six.

Indian Chief can join trainer Aidan O’Brien’s crew of Epsom Derby hopefuls with a strong showing Thursday at York in the Group 2 Dante Stakes, one of England’s major Derby preps.

While Kingsbarns, O’Brien’s leading 2-year-old of 2012, is behind schedule and doubtful to make the Epsom Derby, the stable still has three horses – Battle of Marengo, Ruler of the World, and Mars – priced at odds of about 10-1 or less in antepost Derby betting.