The pregnancy will take 21 months

Anthony Tropeano, the zoo's curator said: "It will be Colchester's first baby elephant.

"Obviously, we are pleased and perhaps especially delighted because if she carries the youngster through full term it will be the first elephant born here at the zoo, and the first born through artificial insemination in this country."

Tembo is also the father of another baby produced by artificial insemination.

In April, Sabi, a female at Vienna Zoo, gave birth to Abu, the first baby produced this way in Europe.

'Early days'

Colchester Zoo said it is too early at this stage to see images of Tanya's baby because the foetus is only the same size as an apple.

The German scientists will return to Colchester Zoo in November to perform further ultrasound examinations and an image of the baby could then be available.

Elephant Birth

Elephant pregnancies last 21 months Labour may last more than two hours Baby elephants weigh between 75 and 150 kg

Tanya, who has lived at the Essex zoo since 1984, is also the only elephant in the world to conceive after only one insemination.

Mr Tropeano said: "Usually it takes two or three attempts, so we are very fortunate. We are stressing that it is very early days for Tanya and her pregnancy.

"Like all pregnancies there is the possibility that she may miscarry, so we are keeping our fingers crossed."

Zoo staff are hoping another elephant, Rosa, is pregnant after having mated naturally with Tembo.