In 1928 Landau reached the quarterfinal of the doubles tournament at the Monaco Championships alongside Ludwig von Salm Hoogstraten.

[4] At the Beausite Club de Cannes Cup in January 1931, he won the doubles contest with his teammate Hillyard.

[13] In March he was a runner-up in the Bordighera Championship doubles, partnering with Béla von Kehrling and only losing to the Irish-Italian duo of George Lyttleton-Rogers and Alberto del Bono.

[15] In the first tournament of the 1932 season in Beaulieu, Landau and Irish champion Lyttleton-Rogers earned the doubles title after a five-set battle.

[1] In April 1947 Landau was summoned to court and to testify in the case of an English woman named Edna Clayton, who was accused of breaching the Defence Finance regulations.

While Clayton was vacationing in Monte Carlo, she ran out of money, and after borrowing some from her host friend she still needed to pay for her trip back to England.

[24][25][26] People who accepted cheques from British subjects in Europe on behalf of Intrator were believed to be aware of the currency crime circle and thus were prosecuted.

[2] The same year their son Patrick Landau was born, who later also became a tennis player and member of the Monaco Davis Cup team.