The former Germany captain and coach Franz Beckenbauer is one of four officials to be investigated by Fifa following “possible undue payments and contracts” relating to the awarding of the 2006 World Cup tournament.

Germany beat South Africa to win the rights to the tournament in 2000 but reports in October last year claimed a slush fund of 10.3 million Swiss francs (£4.8m) had been set up to buy votes. The German Football Association (DFB) denied this but Fifa’s ethics committee has opened formal proceedings against six officials in total after examining a report commissioned by the DFB.

Beckenbauer, the former DFB president Theo Zwanziger, the former secretary general Horst Schmidt and former chief finance officer Stefan Hans will be investigated by Fifa. All were involved in Germany’s World Cup local organising committee, of which Beckenbauer was president.

Fifa’s investigatory chamber will also open proceedings against Wolfgang Niersbach, the former president of the DFB and current member of the Fifa and Uefa executive committees, and the former DFB secretary general Helmut Sandrock. The pair will be investigated for a “possible failure to report a breach” of the ethics code.

Niersbach, who stepped down as president of the DFB in November, has previously insisted that the organising committee had acted both “fairly” and “legally”, saying: “The World Cup was not bought. What was a summer fairytale remains a summer fairytale.” However, Zwanziger later stated that a slush fund had existed.

A Fifa statement read: “In the cases of Messrs Niersbach and Sandrock, the investigatory chamber will investigate a possible failure to report a breach of the Fifa code of ethics, which could constitute a breach of art. 13 (General rules of conduct), art. 15 (Loyalty), art. 18 (Duty of disclosure, cooperating and reporting) and art. 19 (Conflicts of interest) of the FCE.

“In the cases of Mr Beckenbauer, Dr Zwanziger, Mr Schmidt and Mr Hans, the investigatory chamber will investigate possible undue payments and contracts to gain an advantage in the 2006 Fifa World Cup host selection and the associated funding, which could constitute a breach of arts 13, 15, 18 and 19 as well as art. 20 (Offering and accepting gifts and other benefits) and art. 21 (Bribery and corruption) of the Fifa code of ethics.”

In October, Beckenbauer, 70, rejected allegations of corruption, saying: “I never gave money to anyone in order to acquire votes so that Germany is awarded the 2006 World Cup. And I am certain that no other member of the bid committee did something like that.”

In November, German police raided the Frankfurt headquarters of the DFB and searched the homes of officials on suspicion of tax evasion linked to the awarding of the tournament, with documents and hard drives seized according to the German news agency DPA.

Last month the Swiss-Italian football administrator Gianni Infantino was elected as Fifa’s new president, beating Bahrain’s Sheikh Salman bin Ebrahim al-Khalifa in the race to succeed Sepp Blatter as head of the maligned world governing body.