Lord Coe is determined to prove to a sceptical public that the International Association of Athletics Federations is committed to ridding the sport of drug cheats.

The former London 2012 chairman beat Ukrainian Sergey Bubka to the most powerful position in world athletics, as he was elected as the new president of the IAAF in a vote at its Congress in Beijing on Wednesday.

The two-time Olympic 1500 metres champion secured the support of the majority of the 207 IAAF member federations who voted, winning by 115 votes to 92.

Coe, who takes office at the end of the World Championships, which gets under way on Saturday, succeeds Lamine Diack, the 82-year-old from Senegal who has been president since 1999, and becomes only the sixth president in the IAAF's 103-year history.

The 58-year-old's elevation from vice-president comes at a crucial time for the organisation, with allegations of mass doping and cover-ups threatening to ruin the already fragile reputation of the sport.

The Briton, who has been a staunch and unapologetic defender of the IAAF's anti-doping record, has pledged to set up an independent anti-doping agency for the sport inside his first 100 days in office. He said: "There is a zero tolerance to the abuse of doping in my sport and I will maintain that to the very highest level of vigilance."

Coe declined to go into the details of how his anti-doping body would work, saying it was something he had to discuss with his IAAF colleagues over the coming weeks.

But he did admit there was a perception that in-house drug testing created "conflicts" and "loopholes".

He added: "We do have to recognise that there is too broad a view that this is something, whether real or perceived, (where) there are conflicts and there are loopholes and I think an independent system is what we need to close down any thought that we are doing anything other than being entirely vigilant about that."

Coe has highlighted the need to overhaul the athletics calendar, increase commercial revenue, empower national federations and encourage young people into the sport.

But it is the fight against banned drugs which is set to be front and centre of his reign.

The IAAF has come under fierce attack amid allegations - which it vehemently denies – that it turned a blind eye to suspicious blood test results from hundreds of athletes and also blocked the publication of a report claiming a third of athletes at the 2011 World Championships in South Korea admitted doping.

Coe has been the most outspoken voice on the accusations, calling them a "declaration of war" on the sport.

Despite the strong rebuttals, it is clear serious damage has been done to the credibility of the organisation and the sport as a whole, an issue which needs to be addressed urgently.

And UK Athletics chairman Ed Warner backed Coe to tackle the doping problem head on.

He said: "If there's one person that I know will pursue cheats to all four corners of the earth it is Seb, who's been passionate about his anti-doping commitment over many years."

World Anti-Doping Agency president Craig Reedie said his organisation looked forward to a "positive and strong relationship" with Coe.

The new president, who received congratulations from the likes of Prime Minister David Cameron, has worked tirelessly to garner support from countries around the world during his campaign, travelling around 700,000 kilometres across the globe since Christmas.

He described his victory as the "second biggest and momentous occasion" of his life after the birth of his children, adding: "This for me is the pinnacle, it's my sport, it's my passion, it's the thing I always wanted to do."

Coe, whose other posts include chairman of the British Olympic Association, executive chairman of CSM Sport and Entertainment - a sports marketing outfit - and global advisor to Nike, said it was too soon to say whether he would have to scale back any of those roles.

He said: "I made the point absolute unflinchingly (to the Congress) this morning, you have a president who will devote full-time attention to the management and the direction of the IAAF. I would not have thrown by hat into the ring if I felt that I would be short changing this organisation.

"How I combine that is something that I've always managed. Anything I have to do to accommodate around the presidency of the federation I will do, but it's very early to give you a definite view of that."

Coe appeared riled when pushed on his links to Nike, saying: "I have only been at Nike since 1978, so that's a fairly new relationship, and I've always managed so far to put that into the right space."

Bubka was re-elected as an IAAF vice-president.