HAMBURG, July 9 (Reuters) - German authorities culled about 1,200 farm and pet birds over the weekend after a pet goose tested positive for the lethal strain of bird flu, a government spokesman said on Monday.

The slaughtering programme had now been completed in an exclusion zone around Wickersdorf in Thueringen in east Germany, a Thueringen state government spokesman said.

A pet goose in a home for mentally handicapped people had tested positive for the lethal H5N1 strain of bird flu and all farm and pet birds in a three-km exclusion zone were culled as a precautionary measure over the weekend, he said.

The affected goose had been able to run around freely and contact with wild birds was suspected as being the cause, he added. Investigations into the infection cause were continuing.

Thueringen had re-introduced a lock-up order for farm poultry which must be kept indoors in areas of high risk contact with wild birds, such as in farms near lakes and rivers.

H5N1 bird flu has been confirmed in a series of wild birds in Germany in the past three weeks in Thueringen, in the eastern state of Saxony and in the southern state of Bavaria.

On July 5, H5N1 bird flu was also confirmed in three wild swans in France.

Last year, some 13 European Union member states had confirmed cases of bird flu -- Germany, Austria, Denmark, Italy, Greece, Britain, the Czech Republic, Poland, Slovakia, Slovenia, Sweden, France and Hungary.

Bird flu has been spreading across southeast Asia, killing two people in Vietnam this month, the first deaths there since 2005.

Globally, the H5N1 virus has killed nearly 200 people out of over 300 known cases, according to the World Health Organisation. None of the victims were from Europe.